Tumor necrosis factor has been implicated in the pathophysiology of psoriatic arthritis (Partsch et al. (1998) Ann Rheum Dis. 57:691; Ritchlin et al. (1998) J Rheumatol. 25:1544). As referred to herein, psoriatic arthritis (PsA) or psoriasis associated with the skin, refers to chronic inflammatory arthritis which is associated with psoriasis. Psoriasis is a common chronic skin condition that causes red patches on the body. About 1 in 20 individuals with psoriasis will develop arthritis along with the skin condition, and in about 75% of cases, psoriasis precedes the arthritis. PsA exhibits itself in a variety of ways, ranging from mild to severe arthritis, wherein the arthritis usually affects the fingers and the spine. When the spine is affected, the symptoms are similar to those of ankylosing spondylitis. The TNFα inhibitor, or TNFα antibody, or antigen-binding fragment thereof, of the invention can be used to treat PsA.